The Retinal Circulation

Melatonin Suppression by Light in Humans Is Maximal When the Nasal Part of the Retina Is Illuminated

“…In the context of this hypothesis, it is conceivable that differences in blood flow and blood vessel density in various parts of the retina would cause the observed differences in sensitivity of melatonin suppression by light. However, no obvious differences in blood flow and blood vessel density are reported between nasal and lateral parts of the retinas (Wise et al, 1971). Adler et al (1992) and Lasko et al (1999 [this issue]) have applied techniques similar to ours to compare the responsiveness of melatonin suppression by light at different exposure sites of the retina.…”

Comparison of amplitude-decorrelation, speckle-variance and phase-variance OCT angiography methods for imaging the human retina and choroid

“…The thickness of this layer measures from 5 µm to 18 µm at the posterior pole of the eye [1,80]. To avoid sectioning through the choriocapillaris layer, the visualization in en face projections should closely follow the shape of the outer edge of the RPE (Bruch's membrane) in the healthy eye.…”

“…We proposed to calculate contrast-to-noise ratio (CNR) between the photoreceptor/RPE complex and the choriocapillaris layer as a metric for evaluation of the OCTA performance in static tissue noise reduction and imaging of the choroid. We demonstrated that implementation of intensity based OCT imaging and OCT angiography methods allows for visualization of retinal and choroidal vascular layers known from anatomic studies with retinal preparations [1]. OCT projection imaging of data flattened to selected retinal layers was implemented to showcase retinal and choroidal vasculature Userguided vessel tracing was applied to segment the retinal vasculature.…”

“…In human ocular anatomy two distinct vascular systems are recognized in the histology and angiographic imaging of the fundus [1,2]: the retinal vasculature and the choroid. Both systems are derived from the ophthalmic artery.…”

Familial exudative vitreoretinopathy and related retinopathies

“…17 In the midperipheral retina, only one further plexus grows at the outer border of the INL; and towards the far periphery, where the retina is thinner, the two vascular layers become less distinct and eventually form one layer ( Figure 1). [18][19][20] A fourth capillary layer is present within the thick NFL around the optic disc and along the temporal vascular arcades. These peripapillary capillaries run radially, in parallel with the retinal nerve fibres, and have few anastamoses.…”